1) Field of the Invention
This invention relates to a portable radio terminal with an infrared communication function and an infrared emission power controlling method between a portable radio terminal and an apparatus with an infrared communication function.
2) Description of the Related Art
In recent years, diversification in form of utilization of a portable radio terminal has been and is proceeding. For example, a portable radio terminal has been proposed which not only has an original radio communication function but also utilizes infrared communication, for which no cable is used, for data communication or like communication which is performed with a terminal such as a personal computer at a comparatively short distance. A portable radio terminal which has an infrared communication function in addition to an original radio communication function in this manner is called portable radio terminal with an infrared communication function.
When such a portable radio terminal with an infrared communication function as just described performs data communication with a terminal such as a personal computer at a comparatively short distance, the terminal-to-terminal communication distance is approximately 100 cm according to the standards of the IrDA (Infrared Data Association). Accordingly, the emission power to be used for infrared communication is set to a value which can sufficiently cover the communication distance.
By the way, such a portable radio terminal with an infrared communication function as described above not only is used to perform data communication with a personal computer or the like as described above, but also is sometimes used while it is set in position on a cradle (which signifies a vehicle-carried adapter having a power supplying function, a hand-free function, a communication function with a portable terminal and so forth. In the following description, the term xe2x80x9ccradlexe2x80x9d is used in the same meaning.) so as to allow hand-free use of the portable radio terminal in a cabin of an automobile. In this instance, for better convenience in use, also the cradle and the portable radio terminal should be connected to each other by infrared communication.
Where such infrared communication between a portable radio terminal and a cradle as described above is considered, while the communication between them is communication over a very short distance of approximately 1 cm, since the emission power to be used for infrared communication is set to a value with which the communication distance of approximately 100 cm can be covered sufficiently, even if communication should be performed over a very short distance between the terminal and the cradle, electric current similar to that consumed in communication over 100 cm is consumed. This reduces the available time of the battery and gives rise to a subject to be solved in that the portable radio terminal cannot be used for a long time. In other words, also in order to satisfy a demand for a long waiting time of a portable radio terminal in recent years, reduction in power consumption in infrared communication is an important subject to a portable radio terminal with an infrared communication function.
It is an object of the present invention to provide a portable radio terminal with an infrared communication function and an infrared emission power controlling method between a portable radio terminal and an apparatus with an infrared communication function by which, even if the communication distance varies, appropriate infrared emission power control can be performed to achieve reduction in power consumption in infrared communication by detecting the other party of infrared communication or a reception power.
In order to attain the object described above, according to an aspect of the present invention, there is provided a portable radio terminal with an infrared communication function, comprising an infrared communication section for transmitting and receiving a signal in an infrared frequency band, communication object party detection means for detecting information of the other party of infrared communication, and control means for controlling an emission power of the infrared communication section in response to information of the other party of infrared communication detected by the communication object party detection means.
With the portable radio terminal with an infrared communication function, even if the communication distance varies, appropriate infrared emission power control can be performed by recognizing the other party of infrared communication or a reception power. As a result, the portable radio terminal with an infrared communication function is advantageous in that, upon communication over a very short distance, low power consumption in infrared communication can be achieved sufficiently, but upon normal infrared communication, infrared communication in a sufficient emission power condition can be performed.
The communication object party detection means may detect the information of the other party of infrared communication from data received from the other party of infrared communication through the infrared communication section or from a connection condition of an external terminal of the portable radio terminal.
Where the information of the other party of infrared communication is detected in this manner, appropriate power control for the other party of infrared communication can be performed and low power consumption can be achieved.
According to another aspect of the present invention, there is provided a portable radio terminal with an infrared communication function which can be placed on and used with a vehicle-carried adapter having a communication function by infrared rays, comprising an infrared communication section for transmitting and receiving a signal in an infrared frequency band, an identification section for identifying the other party of infrared communication, and a control section for decreasing, when the identification section detects that the other party of infrared communication is the vehicle-carried adapter, an emission power of the infrared communication section from an normal emission power.
With the portable radio terminal with an infrared communication function, there is an advantage that, upon communication over such a very short distance as in a case wherein the portable radio terminal is placed on the vehicle-carried adapter, the emission power can be decreased, and consequently, low power consumption in infrared communication can be achieved sufficiently.
According to a further aspect of the present invention, there is provided a portable radio terminal with an infrared communication function, comprising an infrared communication section for transmitting and receiving a signal in an infrared frequency band, reception power detection means for detecting reception power information from the other party of infrared communication, communication object party detection means for detecting infrared communication object party information, and control means for controlling an emission power of the infrared communication section using the reception power information detected by the reception power detection means and the infrared communication object party information detected by the communication object party detection means.
According to a still further aspect of the present invention, there is provided an infrared emission power controlling method between a portable radio terminal with an infrared communication function and an apparatus with an infrared communication function when a signal in an infrared frequency band is communicated between the portable radio terminal with an infrared communication function and the apparatus with an infrared communication function, comprising the step performed by at least one of the portable radio terminal and the apparatus of controlling an infrared emission power using reception power information from the other party of infrared communication and infrared communication object party information detected by communication object party detection means.
With the portable radio terminal with an infrared communication function and the infrared emission power controlling method, there is an advantage that, upon communication over a very short distance, fine control can be performed when the emission power is decreased from a high power to a low power and low power consumption in infrared communication can be achieved sufficiently, but upon normal infrared communication, infrared communication in a sufficient emission power condition can be performed.
According to a yet further aspect of the present invention, there is provided a portable radio terminal with an infrared communication function, comprising an infrared communication section for transmitting and receiving a signal in an infrared frequency band, reception power information reception means for receiving reception power information detected by and transmitted from the other party of infrared communication, and control means for controlling an emission power of the infrared communication section in response to the reception power information received by the reception power information reception means.
According to a yet further aspect of the present invention, there is provided an infrared emission power controlling method between a portable radio terminal with an infrared communication function and an apparatus with an infrared communication function when a signal in an infrared frequency band is communicated between the portable radio terminal with an infrared communication function and the apparatus with an infrared communication function, comprising the steps performed by at least one of the portable radio terminal and the apparatus of receiving reception power information detected by and transmitted from the other party of infrared communication, and controlling an infrared emission power based on a result of the detection.
Also with the portable radio terminal with an infrared communication function and the infrared emission power controlling method, there is an advantage that, upon communication over a very short distance, fine control can be performed when the emission power is decreased to a high power to a low power and low power consumption in infrared communication can be achieved sufficiently, but upon normal infrared communication, infrared communication in a sufficient emission power condition can be performed.
According to a yet further aspect of the present invention, there is provided a portable radio terminal with an infrared communication function, comprising an infrared communication section for transmitting and receiving a signal in an infrared frequency band, reception power detection means for detecting reception power information from the other party of infrared communication, and control means for controlling an emission power of the infrared communication section in response to the reception power information detected by the reception power detection means.
According to a yet further aspect of the present invention, there is provided an infrared emission power controlling method between a portable radio terminal and an apparatus with an infrared communication function when a signal in an infrared frequency band is communicated between the portable radio terminal with an infrared communication function and the apparatus with an infrared communication function, comprising the steps performed by at least one of the portable radio terminal and the apparatus of detecting reception power information from the other party of infrared communication, and controlling an infrared emission power based on a result of the detection.
With the portable radio terminal with an infrared communication function and the infrared emission power controlling method, there is an advantage that, upon communication over a very short distance, low power consumption in infrared communication can be achieved sufficiently, but upon normal infrared communication, infrared communication in a sufficient emission power condition can be performed.
According to a yet further aspect of the present invention, there is provided an infrared emission power controlling method between a portable radio terminal with an infrared communication function and an apparatus with an infrared communication function when a signal in an infrared frequency band is communicated between the portable radio terminal with an infrared communication function and the apparatus with an infrared communication function, comprising the steps performed by at least one of the portable radio terminal and the apparatus of detecting information of the other party of infrared communication, and controlling an infrared emission power based on a result of the detection.
With the infrared emission power controlling method, there is an advantage that infrared communication can be performed varying the infrared emission power depending upon the other party of infrared communication and, upon communication over a very short distance, the emission power can be suppressed, but communication over a long distance, a sufficient emission power can be outputted, and low power consumption can be achieved.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements denoted by like reference symbols.